Can't imagine how the radio and wipers would be affected by a starting circuit problem, but with so many unrelated things acting up, I'd suspect a battery or generator problem. First check for loose or dirty battery cables, then see if it will start with a jump-start or after using a battery charger on a low charge rate for an hour. Use an inexpensive digital voltmeter to measure the battery voltage. It should be 12.6 volts. If it's around 12.0 volts, it's good but discharged. If it's closer to 11.0 volts or less, a cell is shorted.
Once the engine is running the battery voltage must be between 13.75 and 14.75 volts. If it is low, suspect the generator. GM has had a very poor generator design since 1987, and it has a very high failure rate. To reduce the number of repeat failures, replace the battery at the same time. As they age, they lose their ability to absorb and dampen the huge voltage spikes these generators produce. It's those spikes that do the damage to the internal diodes and voltage regulator and can interfere with other computers on the car. The old battery may work fine in a 1986 or older car.
Friday, December 2nd, 2011 AT 1:38 AM